Create empty relocations section

TODO

@@ -3,3 +3,16 @@
 - Put symbol table in the reader monad and it to the stack
   or use the state monad for everything.
 - Add errors handling to the monad stack.
+
+# ELF generation
+- Define SHF_ constants.
+- Don't ignore relocations where the symbol is not defined in the symbol table.
+  Add it as an external symbol to the symbol table.
+- Since every function adds a section header use a state monad
+  in the generator and put the headers into the state to reduce the number of
+  returned values in the tuples.
+- Relocation section header relates to another section (e.g. .rel.text). The
+  index of that section should be passed together with collected relocations.
+- symstrtab creates 3 section headers and does some math to calculate the
+  offsets and names. Introducing the state monad can help to get rid of magic
+  numbers.